Optical Filters

Abstract

To provide an optical filter having ripples and stray light suppressed in a visible light region, and having excellent transparency in the visible light region and shielding properties in a near infrared light region.SOLUTION: An optical filter according to the present invention comprises a base material, a dielectric multilayer film 1 stacked as an outermost layer on one main surface side of the base material, and a dielectric multilayer film 2 stacked as an outermost layer on the other main surface side of the base material. The base material has a near infrared ray absorption glass and a resin film. The resin film is 10 μm or less in thickness, and includes a resin and a dye (NIR1). The optical filter satisfies all of predetermined spectral characteristics (i-1) to (i-5), (i-7), (i-8), (i-12), and (i-14).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical filter that transmits visible light and blocks near-infrared light. [Background technology]

[0002] In order to reproduce color tones well and obtain clear images, imaging devices using solid-state imaging elements use optical filters that transmit light in the visible range (hereinafter also referred to as "visible light") and block light in the near-infrared wavelength range (hereinafter also referred to as "near-infrared light").

[0003] Such optical filters can be made in various ways, for example, by laminating dielectric thin films with different refractive indices alternately on one or both sides of a transparent substrate (dielectric multilayer film), and using optical interference to reflect light that needs to be blocked, such as a reflective filter.

[0004] Patent Documents 1 and 2 describe optical filters having a dielectric multilayer film and an absorption layer containing a dye. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 002864 [Patent Document 2] International Publication No. 2018 / 043564 Summary of the Invention [Problem to be solved by the invention]

[0006] Optical filters with dielectric multilayer films have a problem in that the optical thickness of the dielectric multilayer film changes depending on the angle of incidence of light, resulting in changes in the spectral transmittance curves and spectral reflectance curves depending on the angle of incidence. For example, depending on the number of layers in the multilayer film, interference caused by reflected light at the interfaces of each layer can cause significant changes in transmittance in the visible light range, known as ripples, which tend to occur more strongly the larger the angle of incidence of light. This causes changes in the amount of light absorbed in the visible light range at high angles of incidence, resulting in reduced image reproducibility. In particular, with the recent trend toward thinner camera modules, use at higher angles of incidence is expected, creating a demand for optical filters that are less susceptible to the effects of the angle of incidence.

[0007] Furthermore, conventional optical filters that utilize the reflection of a dielectric multilayer film can cause stray light, a phenomenon in which light is emitted outside the intended optical path, due to reflected light being re-reflected by a lens surface or light reflected by a sensor surface being re-reflected by a dielectric multilayer film surface. The use of such filters can result in flare and ghosting in solid-state imaging devices, leading to image quality degradation. In particular, with the recent trend toward higher image quality in camera modules, optical filters that are less susceptible to stray light are in demand.

[0008] An object of the present invention is to provide an optical filter that suppresses ripples and stray light in the visible light region and has excellent transmittance in the visible light region and excellent shielding properties in the near-infrared light region. [Means for solving the problem]

[0009] The present invention provides an optical filter and the like having the following configuration. [1] An optical filter comprising a substrate, a dielectric multilayer film 1 laminated as an outermost layer on one main surface side of the substrate, and a dielectric multilayer film 2 laminated as an outermost layer on the other main surface side of the substrate, the substrate has a near-infrared absorbing glass and a resin film, the resin film has a thickness of 10 μm or less and contains a resin and a dye (NIR1); The optical filter satisfies all of the following spectral characteristics (i-1) to (i-5), (i-7), (i-8), (i-12), and (i-14). (i-1) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 450-600(0deg)AVE Over 85% (i-2) In the spectral transmittance curve at an incident angle of 0 degrees, the maximum transmittance T 450-600(0deg)MAX Over 90% (i-3) The average transmittance T 450-600(0deg)AVE and the average transmittance T of the spectral transmittance curve for wavelengths from 450 to 600 nm at an incident angle of 50 degrees. 450-600(50deg)AVE The absolute difference between (i-4) In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance T at a wavelength of 450 nm 450(0deg) Over 80% (i-5) In the spectral transmittance curve at an incident angle of 0 degrees, the wavelength IR50 at which the transmittance is 50% (0deg) is in the range of 610-650 nm (i-7) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 700-1000(0deg)AVE is less than 2% (i-8) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T 700-1000(50deg)AVE is less than 2% (i-12) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less (i-14) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less [Effects of the Invention]

[0010] According to the present invention, an optical filter can be provided that suppresses ripples and stray light in the visible light region and has excellent transmittance in the visible light region and excellent blocking properties in the near-infrared light region. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an example of an optical filter according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing another example of the optical filter according to the embodiment. [Figure 3] FIG. 3 is a diagram showing the spectral transmittance curve of the near-infrared absorbing glass. [Figure 4] FIG. 4 is a diagram showing the spectral transmittance curve of the resin film of Example 1-1. [Figure 5] FIG. 5 is a diagram showing the spectral transmittance curve of the substrate of Example 2-1. [Figure 6] FIG. 6 is a diagram showing the spectral transmittance curve of the optical filter of Example 4-1. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described. In this specification, the near-infrared absorbing dye may be abbreviated as "NIR dye" and the ultraviolet absorbing dye may be abbreviated as "UV dye". In this specification, a compound represented by formula (I) is referred to as compound (I). The same applies to compounds represented by other formulas. A dye consisting of compound (I) is also referred to as dye (I), and the same applies to other dyes. Furthermore, a group represented by formula (I) is also referred to as group (I), and the same applies to groups represented by other formulas.

[0013] In this specification, the internal transmittance is the transmittance obtained by subtracting the influence of interface reflection from the measured transmittance, as expressed by the formula {measured transmittance / (100-reflectance)}×100. In this specification, the transmittance of a substrate and the transmittance of a resin film, including a case where a dye is contained in the resin, are all referred to as "internal transmittance" even when they are referred to as "transmittance." On the other hand, the transmittance measured by dissolving a dye in a solvent such as dichloromethane, the transmittance of a dielectric multilayer film, and the transmittance of an optical filter having a dielectric multilayer film are actually measured transmittances.

[0014] In this specification, for example, a transmittance of 90% or more in a specific wavelength range means that the transmittance is not less than 90% across the entire wavelength range, i.e., the minimum transmittance is 90% or more across the wavelength range. Similarly, for example, a transmittance of 1% or less in a specific wavelength range means that the transmittance is not more than 1% across the entire wavelength range, i.e., the maximum transmittance is 1% or less across the wavelength range. The same applies to internal transmittance. The average transmittance and average internal transmittance in a specific wavelength range are the arithmetic mean of the transmittance and internal transmittance per 1 nm in the wavelength range. The spectral characteristics can be measured using an ultraviolet-visible spectrophotometer. In this specification, the use of "to" to indicate a range of values ​​includes the upper and lower limits.

[0015] <Optical filters> An optical filter according to one embodiment of the present invention (hereinafter also referred to as "this filter") comprises a substrate, a dielectric multilayer film 1 laminated as the outermost layer on one main surface side of the substrate, and a dielectric multilayer film 2 laminated as the outermost layer on the other main surface side of the substrate. The substrate includes a near-infrared absorbing glass and a resin film having a thickness of 10 μm or less laminated on at least one main surface of the near-infrared absorbing glass. The resin film further includes a resin and a dye (NIR1) having a maximum absorption wavelength in the resin at 680 to 740 nm. The reflection characteristics of the dielectric multilayer film and the absorption characteristics of the substrate containing the near-infrared absorbing glass and near-infrared absorbing dye enable the optical filter as a whole to achieve excellent transmittance in the visible light region and excellent blocking properties in the near-infrared light region.

[0016] An example of the configuration of the present filter will be described with reference to the drawings. Figures 1 and 2 are cross-sectional views that schematically show an example of an optical filter according to an embodiment.

[0017] 1 is an example in which a dielectric multilayer film 20A is provided on one main surface side of a substrate 10 having a near-infrared absorbing glass 11 and a resin film 12, and a dielectric multilayer film 20B is provided on the other main surface side. Note that "having a specific layer on the main surface side of the substrate" does not only mean that the layer is provided in contact with the main surface of the substrate, but also means that another functional layer is provided between the substrate and the layer.

[0018] The optical filter 1C shown in FIG. 2 is an example in which the substrate 10 has resin films 12A and 12B on both main surfaces of the near-infrared absorbing glass 11, and the substrate 10 has dielectric multilayer films 20A and 20B on both main surfaces.

[0019] The optical filter of the present invention satisfies all of the following spectral characteristics (i-1) to (i-14). (i-1) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 450-600(0deg)AVE Over 85% (i-2) In the spectral transmittance curve at an incident angle of 0 degrees, the maximum transmittance T 450-600(0deg)MAX Over 90% (i-3) The average transmittance T 450-600(0deg)AVE and the average transmittance T of the spectral transmittance curve for wavelengths from 450 to 600 nm at an incident angle of 50 degrees. 450-600(50deg)AVE The absolute difference between (i-4) In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance T at a wavelength of 450 nm 450(0deg) Over 80% (i-5) In the spectral transmittance curve at an incident angle of 0 degrees, the wavelength IR50 at which the transmittance is 50% (0deg) is in the range of 610-650 nm (i-6) The wavelength IR50 (0deg) In the spectral transmittance curve at an incident angle of 50 degrees, the wavelength at which the transmittance is 50% is IR50 (50deg) The absolute value of the difference is 10 nm or less (i-7) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 700-1000(0deg)AVE is less than 2% (i-8) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T700-1000(50deg)AVE is less than 2% (i-9) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 1000-1200(0deg)AVE is less than 5% (i-10) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T 1000-1200(50deg)AVE is less than 5%

[0020] (i-11) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 at a wavelength of 450 to 600 nm 450-600(5deg)MAX is less than 2% (i-12) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less

[0021] (i-13) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 450 to 600 nm 450-600(5deg)MAX is less than 3% (i-14) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less

[0022] This filter, which satisfies all of the spectral characteristics (i-1) to (i-14), has low reflectance in the visible and near-infrared regions in any direction of the optical filter's main surface, as shown in characteristics (i-11) to (i-14), and can suppress reflected light that causes stray light. It also has high visible light transmittance, as shown in characteristics (i-1), (i-2), and (i-4), and high near-infrared blocking, as shown in characteristics (i-7) to (i-10). Furthermore, as shown in characteristics (i-3) and (i-6), there is little change in the spectral characteristics at high angles of incidence, and ripple in the visible light region is suppressed.

[0023] Satisfying the spectral characteristics (i-1) to (i-2) means that the transmittance in the visible light region of 450 to 600 nm is excellent. T 450-600(0deg)AVE is preferably 86% or more, more preferably 88% or more. T 450-600(0deg)MAX is preferably 92% or more, more preferably 93% or more.

[0024] By satisfying the spectral characteristic (i-3), the visible light transmittance in the range of 450 to 600 nm is unlikely to change even at a high angle of incidence, which means that ripples are suppressed. The absolute value of the spectral characteristic (i-3) is preferably 3% or less, more preferably 2% or less.

[0025] Satisfying the spectral characteristic (i-4) means that the transmittance in the blue light region is excellent. T 450(0deg) is preferably 84% or more, more preferably 85% or more.

[0026] By satisfying the spectral characteristics (i-5), it is possible to block light in the near-infrared region and efficiently capture transmitted visible light. IR50 (0deg) is preferably 615 to 640 nm, more preferably 615 to 635 nm.

[0027] Satisfying the spectral characteristic (i-6) means that the spectral curve in the 610 to 650 nm region is less likely to shift even at high angles of incidence. The absolute value of the spectral characteristic (i-6) is preferably 9 nm or less, more preferably 8 nm or less.

[0028] Satisfying the spectral characteristics (i-7) to (i-8) means that the light blocking properties in the infrared region of 700 to 1000 nm are excellent even at high angles of incidence. T 700-1000(0deg)AVE is preferably 1.2% or less, more preferably 1.0% or less. T 700-1000(50deg)AVE is preferably 1.2% or less, more preferably 1.0% or less.

[0029] Satisfying the spectral characteristics (i-9) to (i-10) means that the film has excellent light-blocking properties in the infrared region of 1000 to 1200 nm even at high angles of incidence. T 1000-1200(0deg)AVE is preferably 2% or less, more preferably 1% or less. T 1000-1200(50deg)AVE is preferably 2% or less, more preferably 1% or less.

[0030] The spectral characteristics (i-11) to (i-12) define the reflection characteristics on the dielectric multilayer film 1 side. The spectral characteristics (i-13) to (i-14) define the reflection characteristics on the dielectric multilayer film 2 side. The low reflectance in either incident direction makes it possible to suppress reflection on the dielectric multilayer film surface, which causes stray light.

[0031] R1 450-600(5deg)MAX is preferably 2.5% or less, more preferably 1.5% or less. R1 600-1200(5deg)MAX is preferably 35% or less, more preferably 25% or less. R2 450-600(5deg)MAX is preferably 2% or less, more preferably 1.5% or less. R2 600-1200(5deg)MAX is preferably 40% or less, more preferably 30% or less.

[0032] The optical filter of the present invention preferably further satisfies the following spectral properties (i-15) to (i-18). (i-15) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 at a wavelength of 450 to 600 nm 450-600(50deg)MAX is 7% or less (i-16) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 600 to 1200 nm 600-1200(50deg)MAX is 45% or less (i-17) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 450 to 600 nm 450-600(50deg)MAX is 7% or less (i-18) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 600 to 1200 nm 600-1200(50deg)MAX is 45% or less

[0033] The spectral characteristics (i-15) to (i-16) define the reflection characteristics on the dielectric multilayer film 1 side at high incident angles. The spectral characteristics (i-17) to (i-18) define the reflection characteristics on the dielectric multilayer film 2 side at high incident angles. The low reflectance in either incident direction and at a high incident angle makes it possible to suppress reflection on the dielectric multilayer film surface, which causes stray light.

[0034] R1 450-600(50deg)MAX is preferably 6.5% or less, more preferably 6% or less. R1 600-1200(50deg)MAX is preferably 40% or less, more preferably 30% or less. R2 450-600(50deg)MAX is preferably 2% or less, more preferably 1.5% or less. R2 600-1200(50deg)MAX is preferably 40% or less, more preferably 30% or less.

[0035] The optical filter of the present invention preferably further satisfies the following spectral properties (i-19) to (i-20). (i-19) In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance at a wavelength of 450 nm is T 450(0deg) The maximum transmittance at wavelengths of 1000 to 1200 nm is the maximum transmittance T 1000-1200(0deg)MAX When the transmittance T 450(0deg) / The maximum transmittance T 1000-1200(0deg)MAX ≧20 (i-20) In the spectral transmittance curve at an incident angle of 50 degrees, the transmittance at a wavelength of 450 nm is T 450(50deg) The maximum transmittance at wavelengths of 1000 to 1200 nm is the maximum transmittance T1000-1200(50deg)MAX When the transmittance T 450(50deg) / The maximum transmittance T 1000-1200(50deg)MAX ≧20

[0036] By satisfying the spectral characteristics (i-19) to (i-20), it means that both the transmittance in the visible light region and the light blocking property in the infrared region are achieved even at high angles of incidence. T 450(0deg) / T 1000-1200(0deg)MAX is preferably 22 or more, more preferably 25 or more. T 450(0deg) / T 1000-1200(50deg)MAX is preferably 30 or more, more preferably 40 or more.

[0037] The optical filter of the present invention preferably further satisfies the following spectral properties (i-21) to (i-28). (i-21) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 450 to 700 nm 450-700(5deg)MAX is 7% or less (i-22) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 450 to 700 nm 450-700(50deg)MAX is 7% or less (i-23) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 700 to 1200 nm 700-1200(5deg)MAX is 45% or less (i-24) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 700 to 1200 nm 700-1200(50deg)MAX is 45% or less (i-25) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 450 to 700 nm 450-700(5deg)MAX is 7% or less (i-26) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 450 to 700 nm 450-700(50deg)MAX is 7% or less (i-27) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 700 to 1200 nm 700-1200(5deg)MAX is 45% or less (i-28) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 700 to 1200 nm 700-1200(50deg)MAX is 45% or less

[0038] By further satisfying the properties (i-21) to (i-28), an optical filter can be obtained in which the reflection from both surfaces has low reflection characteristics over a wide wavelength range. R1 450-700(5deg)MAX is preferably 3% or less, more preferably 2% or less. R1 450-700(50deg)MAX is preferably 6.5% or less, more preferably 6% or less. R1 700-1200(5deg)MAX is preferably 35% or less, more preferably 25% or less. R1 700-1200(50deg)MAX is preferably 35% or less, more preferably 25% or less.

[0039] R2 450-700(5deg)MAX is preferably 3% or less, more preferably 2% or less. R2 450-700(50deg)MAX is preferably 6.5% or less, more preferably 6% or less. R2 700-1200(5deg)MAX is preferably 35% or less, more preferably 25% or less. R2 700-1200(50deg)MAX is preferably 35% or less, more preferably 25% or less.

[0040] The optical filter of the present invention preferably further satisfies the following spectral properties (i-29) to (i-33). (i-29) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 360-400(0deg)AVE is less than 2% (i-30) The average transmittance T of the spectral transmittance curve at an incident angle of 50 degrees from 360 to 4000 nm360-400(50deg)AVE is less than 2% (i-31) In the spectral transmittance curve at an incident angle of 0 degrees, the wavelength at which the transmittance is 50% is UV50 (0deg) is in the range of 400-440 nm (i-32) In the spectral transmittance curve at an incident angle of 50 degrees, the wavelength at which the transmittance is 50% is UV50 (50deg) is in the range of 400-440 nm (i-33) The wavelength UV50 (0deg) and the wavelength UV50 (50deg) The absolute difference is 3 nm or less

[0041] Satisfying the spectral characteristics (i-29) to (i-30) means that the film has excellent light-blocking properties in the near-ultraviolet region of 360 to 400 nm even at high angles of incidence. T 360-400(0deg)AVE is preferably 1.5% or less, more preferably 1% or less. T 360-400(50deg)AVE is preferably 1.5% or less, more preferably 1% or less.

[0042] By satisfying the spectral characteristics (i-31) to (i-32), it is possible to block the near-ultraviolet region and efficiently capture transmitted visible light. By satisfying the spectral characteristic (i-33), it means that the spectral curve in the region of 400 to 440 nm is less likely to shift even at high angles of incidence. UV50 (0deg) is preferably 400 to 430 nm, more preferably 410 to 430 nm. UV50 (50deg) is preferably 400 to 430 nm, more preferably 410 to 430 nm. The absolute value of the spectral characteristic (i-33) is preferably 2.5 nm or less, more preferably 2 nm or less.

[0043] <Dielectric multilayer film> In this filter, the dielectric multilayer film is laminated as the outermost layer on both main surfaces of the substrate. The dielectric multilayer film 1 is laminated on one main surface of the substrate, and the dielectric multilayer film 2 is laminated on the other main surface of the substrate.

[0044] In the present filter, it is preferable that the dielectric multilayer film 1 and the dielectric multilayer film 2 satisfy all of the following spectral characteristics (v-1) to (v-4). (v-1) The minimum transmittance T in the wavelength range of 450 to 600 nm in the spectral transmittance curve at an incident angle of 0 degrees 450-600(0deg)MIN Over 90% (v-2) The minimum transmittance T in the wavelength range of 450 to 600 nm in the spectral transmittance curve at an incident angle of 50 degrees 450-600(50deg)MIN Over 90% (v-3) The minimum transmittance T in the wavelength range of 600 to 1200 nm in the spectral transmittance curve at an incident angle of 0 degrees 600-1200(0deg)MIN More than 50% (v-4) The minimum transmittance T in the wavelength range of 600 to 1200 nm in the spectral transmittance curve at an incident angle of 50 degrees 600-1200(50deg)MIN More than 50%

[0045] By satisfying the spectral characteristics (v-1) to (v-4), it means that the multilayer film has high visible light transmittance, little light blocking in the near-infrared region, and further has little angle dependency, resulting in little spectral change even at high angles of incidence. T 450-600(0deg)MIN is more preferably 92% or more, and even more preferably 93% or more. T 450-600(50deg)MIN is more preferably 90.5% or more, and even more preferably 91% or more. T 600-1200(0deg)MIN is more preferably 60% or more, and even more preferably 70% or more. T 600-1200(50deg)MIN is more preferably 60% or more, and even more preferably 70% or more.

[0046] As shown in the above spectral characteristics (v-1) to (v-2), the dielectric multilayer film of the present invention exhibits little change in visible light transmittance even at high incident angles, thereby making it possible to suppress the occurrence of ripples. As shown in the above spectral characteristics (v-1) to (v-4), the dielectric multilayer film of the present invention preferably has high transmittance in the visible light region and gently blocks light in the near-infrared region. If the dielectric multilayer film is designed to have high reflectivity, when the optical filter is mounted in an imaging device or the like, light incident from a lens may be reflected by the dielectric multilayer film surface of the optical filter and then re-reflected by the lens surface (front surface), or light incident from the lens and transmitted through the optical filter may be reflected by the sensor surface (rear surface) and then re-reflected by the dielectric multilayer film surface of the optical filter (stray light). Such re-reflected light may cause stray light. In the present invention, stray light is suppressed by designing the dielectric multilayer film to minimize the reflectivity. The light-blocking ability in the near-infrared region that cannot be completely blocked by the reflectivity of the dielectric multilayer film is compensated for by the absorption properties of the substrate, which will be described later. As a result, the present invention provides an optical filter with excellent near-infrared light-blocking ability as a whole.

[0047] In the present filter, it is preferable that each of the dielectric multilayer films is designed as a near-infrared antireflection layer (hereinafter also referred to as an NIR antireflection layer).

[0048] The NIR anti-reflection layer is made up of, for example, a dielectric multilayer film in which dielectric films with different refractive indices are alternately stacked. Examples of the dielectric film include a dielectric film with a low refractive index (low refractive index film) and a dielectric film with a high refractive index (high refractive index film), and it is preferable to alternately laminate these.

[0049] The high refractive index film preferably has a refractive index of 1.6 or more, more preferably 2.2 to 2.5. Examples of materials for the high refractive index film include Ta2O5, TiO2, TiO, Ti2O3, and Nb2O5. Other commercially available products include OS50 (Ti3O5), OS10 (Ti4O7), OA500 (a mixture of Ta2O5 and ZrO2), and OA600 (a mixture of Ta2O5 and TiO2), all manufactured by Canon Optron. Of these, TiO2 is preferred from the standpoints of film formability, reproducibility in terms of refractive index, stability, and the like.

[0050] The low refractive index film preferably has a refractive index of less than 1.6, more preferably 1.4 to 1.5. Examples of materials for the low refractive index film include SiO2, SiO x N y , MgF2, etc. Other commercially available products include S4F and S5F (a mixture of SiO2 and AlO2) manufactured by Canon Optron Inc. Of these, SiO2 is preferred from the standpoint of reproducibility, stability, economy, etc. in film formation.

[0051] As described above, in order to obtain a dielectric multilayer film with suppressed reflection characteristics, it is possible to combine several types of dielectric films with different spectral characteristics when transmitting and selecting a desired wavelength band.

[0052] The NIR antireflection layer preferably has a total number of laminated dielectric multilayer films of 10 or less, more preferably 9 or less, and even more preferably 8 or less. In order to suppress reflection in the visible wavelength range even when the angle of incidence changes, a film with low reflectivity over the entire wavelength range is preferred, rather than a film that reflects only specific wavelengths. The overall thickness of the antireflection layer is preferably 200 to 600 μm. It is preferable that the antireflection layer formed of the dielectric multilayer film 1 and the antireflection layer formed of the dielectric multilayer film 2 each satisfy the above-mentioned number of layers and film thickness.

[0053] The dielectric multilayer film can be formed by vacuum film-forming processes such as CVD, sputtering, and vacuum deposition, or wet film-forming processes such as spraying and dipping.

[0054] The NIR antireflection layer may be a single layer (a group of dielectric multilayer films) that provides the desired optical properties, or two layers that provide the desired optical properties. When there are two or more layers, the antireflection layers may have the same or different compositions.

[0055] The antireflection layer composed of dielectric multilayer film 1 or dielectric multilayer film 2 may be laminated on either main surface of the substrate, but it is usually preferable that dielectric multilayer film 1 be laminated on the near-infrared absorbing glass side and dielectric multilayer film 2 be laminated on the resin film side. When the optical filter is mounted on an imaging device, dielectric multilayer film 1 is placed on the lens side and dielectric multilayer film 2 is placed on the sensor side.

[0056] <Base material> In the optical filter of the present invention, the substrate has a near-infrared absorbing glass and a resin film having a thickness of 10 μm or less. The resin film contains a resin and a dye (NIR1) that has a maximum absorption wavelength in the resin at 680 to 740 nm, and is laminated on at least one main surface of the near-infrared absorbing glass.

[0057] <Spectral characteristics of substrate> The substrate preferably satisfies all of the following spectral properties (ii-1) to (ii-7). (ii-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 84% (ii-2) Maximum internal transmittance T in the wavelength range of 450 to 600 nm 450-600MAX Over 90% (ii-3) Internal transmittance T at a wavelength of 450 nm 450 Over 80% (ii-4) The wavelength IR50 at which the internal transmittance is 50% is in the range of 610 to 650 nm. (ii-5) Average internal transmittance T at wavelength 750~1000nm 750-1000AVE is 1.5% or less (ii-6) Maximum internal transmittance T at wavelengths of 1000 to 1200 nm 1000-1200MAX is less than 5% (ii-7) The internal transmittance T 450 / The maximum internal transmittance T 1000-1200MAX ≧15

[0058] Satisfying the spectral characteristics (ii-1) and (ii-2) means that the transmittance in the visible light region of 450 to 600 nm is excellent. T 450-600AVEis preferably 85% or more, more preferably 86% or more. T 450-600MAX is preferably 92% or more, more preferably 93% or more.

[0059] Satisfying the spectral characteristic (ii-3) means that the transmittance in the blue light region is excellent. T 450 is preferably 83% or more, more preferably 85% or more.

[0060] By satisfying the spectral characteristic (ii-4), it is possible to block light in the near-infrared region and efficiently capture transmitted visible light. IR50 is preferably in the range of 615 to 640 nm, more preferably 615 to 635 nm.

[0061] Satisfying the spectral characteristic (ii-5) means that the film has excellent light-blocking properties in the near-infrared region of 750 to 1000 nm. T 750-1000AVE is preferably 1% or less, more preferably 0.7% or less.

[0062] Satisfying the spectral characteristic (ii-6) means that the film has excellent light-blocking properties in the infrared region of 1000 to 1200 nm. T 1000-1200MAX is preferably 4.5% or less, more preferably 4.3% or less.

[0063] By satisfying the spectral characteristic (ii-7), it means that both the transparency in the visible light region and the light blocking property in the infrared region are achieved. T 450 / T 1000-1200MAX is preferably 17 or more, more preferably 19 or more.

[0064] In the present invention, the substrate has excellent transmittance in the visible light region and excellent light-shielding properties in the near-infrared and infrared regions, as shown in the above-mentioned spectral characteristics (ii-1) to (ii-7). In particular, the high light-shielding properties in the near-infrared and infrared regions can complement the light-shielding properties of the dielectric multilayer film described above.

[0065] In the present invention, the substrate has both the absorption ability of the near-infrared absorbing glass and the absorption ability of the resin film containing the near-infrared absorbing dye (NIR1).

[0066] <Near-infrared absorbing glass> The near-infrared absorbing glass preferably satisfies all of the following spectral properties (iii-1) to (iii-6). (iii-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 90% (iii-2) Internal transmittance T at a wavelength of 450 nm 450 Over 92% (iii-3) The wavelength IR50 at which the internal transmittance is 50% is in the range of 625 to 650 nm (iii-4) Average internal transmittance T at wavelength 750~1000nm 750-1000AVE is 2.5% or less (iii-5) Maximum internal transmittance T in the wavelength range of 1000 to 1200 nm 1000-1200MAX is less than 5% (iii-6) Internal transmittance T 450 / Maximum internal transmittance T 1000-1200MAX ≧10

[0067] Satisfying the spectral characteristic (iii-1) means that the transmittance is excellent in the visible light region of 450 to 600 nm, and satisfying the spectral characteristic (iii-2) means that the transmittance is excellent in the blue light region. T 450-600AVE is preferably 94% or more, more preferably 95% or more. T 450 is preferably 83% or more, more preferably 85% or more.

[0068] By satisfying the spectral characteristic (iii-3), it is possible to block light in the near-infrared region and efficiently capture transmitted visible light. IR50 is preferably in the range of 625 to 645 nm, more preferably 625 to 640 nm.

[0069] Satisfying the spectral characteristic (iii-4) means that the film has excellent light-blocking properties in the near-infrared region of 750 to 1000 nm. T 750-1000AVE is preferably 2% or less, more preferably 1.2% or less.

[0070] Satisfying the spectral characteristic (iii-5) means that the film has excellent light-blocking properties in the infrared region of 1000 to 1200 nm. T 1000-1200MAX is preferably 4.8% or less, more preferably 4.5% or less.

[0071] By satisfying the spectral characteristic (iii-6), it means that both the transmittance in the visible light region and the light blocking property in the infrared region are achieved. T 450 / T 1000-1200MAX is preferably 15 or more, more preferably 18 or more.

[0072] In the present invention, it is preferable that the near-infrared absorbing glass starts absorbing near-infrared light in the region of 625 to 650 nm as shown in the above characteristic (iii-3), and exhibits high light-shielding properties beyond 750 nm as shown in the above characteristic (iii-4), thereby obtaining a substrate that can supplement the light-shielding properties of the above-mentioned dielectric multilayer film.

[0073] The near-infrared absorbing glass is not limited as long as it can provide the above-mentioned spectral characteristics, and examples thereof include absorption-type glasses such as fluorophosphate-based glasses and phosphate-based glasses containing copper ions. Among these, phosphate-based glasses are preferred from the viewpoint of facilitating the above-mentioned spectral characteristics. Note that "phosphate-based glasses" also include silicophosphate glasses in which part of the glass skeleton is composed of SiO2.

[0074] For example, it is preferable that the phosphate-based glass contains the following glass-constituting components: The content of each of the following glass-constituting components is expressed as mass % converted to oxide. P2O5 is the main component that forms glass (glass-forming oxide) and is an essential component for improving near-infrared blocking properties, but if it is less than 65%, the effect is not sufficiently obtained, and if it exceeds 74%, the melting temperature increases and the transmittance in the visible range decreases, which is not preferable. The content is preferably 67 to 73%, and more preferably 68 to 72%. Al2O3 is an essential component for improving weather resistance, but if it is less than 5%, this effect is not sufficiently obtained, and if it exceeds 10%, the melting temperature of the glass increases, and the near-infrared blocking property and visible light transmittance decrease, which is undesirable. The content is preferably 6 to 10%, and more preferably 7 to 9%. B2O3 is an essential component for lowering the melting temperature of glass, but if it is less than 0.5%, this effect is not sufficiently obtained, and if it exceeds 3%, the near-infrared blocking properties are reduced, which is undesirable. The content is preferably 0.7 to 2.5%, and more preferably 0.8 to 2.0%. Li2O is not an essential component, but it has the effect of lowering the melting temperature of the glass, but if it exceeds 10%, the glass becomes unstable, which is undesirable. The content is preferably 0 to 5%, and more preferably 0 to 3%. Na2O is an essential component for lowering the melting temperature of glass, but if it is less than 3%, this effect is not sufficiently obtained, and if it exceeds 10%, the glass becomes unstable, which is undesirable. The content is preferably 4 to 9%, and more preferably 5 to 9%. Li2O + Na2O are essential components for lowering the melting temperature of glass, but if the content is less than 3%, the effect is insufficient, and if it exceeds 15%, the glass becomes unstable, which is undesirable. The content is preferably 4 to 13%, and more preferably 5 to 10%.

[0075] Although MgO is not an essential component, it has the effect of increasing the stability of the glass, but if it exceeds 2%, the near-infrared blocking ability decreases, which is undesirable. Preferably, it is 1% or less, and it is more preferable that MgO is not contained at all. Although CaO is not an essential component, it has the effect of increasing the stability of the glass, but if it exceeds 2%, the near-infrared blocking ability decreases, which is undesirable. The content is preferably 1.5% or less, and it is more preferable that CaO is not contained at all. Although SrO is not an essential component, it has the effect of increasing the stability of the glass, but if it exceeds 5%, the near-infrared blocking ability decreases, which is undesirable. The content is preferably 0 to 4%, and more preferably 0 to 3%. BaO is an essential component for lowering the melting temperature of glass, but if it is less than 3%, this effect is not sufficiently obtained, and if it exceeds 9%, the glass becomes unstable, which is undesirable. The content is preferably 3 to 8%, and more preferably 4 to 8%. MgO+CaO+SrO+BaO are essential components for increasing the stability of glass and lowering the melting temperature of glass, but if the content is less than 3%, the effect is insufficient, and if it exceeds 15%, the glass becomes unstable, which is undesirable. The content is preferably 3 to 12%, and more preferably 4 to 10%.

[0076] CuO is an essential component for improving near-infrared blocking properties, but if it is less than 0.5%, the effect is not sufficiently obtained, and if it exceeds 20%, the visible transmittance decreases, which is undesirable. The content is preferably 1 to 15%, more preferably 2 to 10%, and most preferably 3 to 9%.

[0077] It is preferable that phosphate-based glass be substantially free of K2O. K2O is known to lower the melting temperature of glass. However, the present inventors have confirmed that when phosphate glass contains both K2O and Na2O, the melting temperature of the glass is higher than when only Na2O is contained without K2O. The reason for this is thought to be as follows: When P2O5 and Na2O are mixed equimolarly, the liquidus temperature is approximately 628°C, as shown in the binary phase diagram. In contrast, when P2O5 and K2O are mixed equimolarly, the liquidus temperature exceeds 800°C, as shown in the binary phase diagram. This suggests that if part of the Na2O in phosphate glass is replaced with K2O, the liquidus temperature tends to rise, and the melting temperature also increases. In this specification, "substantially free" means that it is not intentionally used as a raw material. unavoidable impurities introduced from raw material components or the manufacturing process are considered to be substantially free. Furthermore, taking into account the aforementioned inevitable impurities, "substantially free" means that the content is 0.05% or less.

[0078] In phosphate-based glass, in order to obtain spectral characteristics with high visible transmittance and low near-infrared transmittance, it is necessary to select copper ions in the glass component, which have absorption in the ultraviolet region and cause low visible transmittance. + Cu has absorption in the near infrared region more than 2+ It is important to have as many as possible. The copper in the glass component is reduced more as the melting temperature of the glass increases, i.e., Cu 2+ is reduced to Cu + Therefore, Cu 2+ In order to make a large amount of , it is effective to make the melting temperature of the glass as low as possible. The melting temperature of the near-infrared cut filter glass of the present invention is preferably 1150°C or lower, more preferably 1100°C or lower, and even more preferably 1080°C or lower. Therefore, the ratio of BaO and B2O3, which have the effect of lowering the melting temperature of glass, is increased relative to Al2O3, which has the effect of raising the melting temperature of glass. The balance of these glass components can be achieved by increasing (BaO + B2O3) / Al2O3, but if it is too large, it will lead to a decrease in weather resistance, so this ratio is in the range of 0.3 to 2.4. Furthermore, this ratio is preferably 0.3 to 2.0, and more preferably 0.5 to 1.5. In phosphate-based glass, in order to obtain spectral characteristics with high transmittance in the visible range and low transmittance in the near-infrared range, specifically, a steep cutoff characteristic for light in the 600 to 700 nm range, it is necessary to use Cu in the glass. 2+ The distortion of the hexagonal structure of Cu is reduced. 2+ The absorption peak of Cu in the glass is shifted to the longer wavelength side. 2+ It is important to further enhance the absorption of light in the near-infrared region by the Therefore, Cu in the glass 2+ To reduce the distortion of the hexacoordinated structure, the number of non-bridging oxygen atoms in the glass must be large, and the field strength of the modifying oxide (field strength is the value obtained by dividing the valence Z by the square of the ionic radius r: Z / r 2 It was thought that it was necessary for the cation to have a small cation surface area (which represents the strength of the cation's attraction to oxygen). In order to increase the number of non-bridging oxygen atoms in glass, it is necessary to increase the amount of P2O5 in the network oxides that form the glass network compared to other network oxides. P2O5 contains more oxygen in its molecules than Al2O3 and B2O3, so Cu 2+ tends to coordinate non-bridging oxygen, and Cu 2+ On the other hand, to improve the weather resistance of glass, it is effective to increase the ratio of Al2O3, which affects weather resistance, to P2O5. Therefore, the balance of the network oxides contained in the glass is P2O5 / Al2O3 in the range of 6.5 to 10. Furthermore, the ratio of these is preferably 7 to 10, and more preferably 7 to 9.5.

[0079] In addition, the smaller the field strength of the modifying oxide in the glass, the smaller the wave number of the absorption peak. 2+ It has been found that the absorption of light in the near-infrared region of the glass increases. To achieve this, it is effective to include a large amount of Na2O, which has a relatively small field strength, compared to other modifying oxides. From this viewpoint, the balance of the modifying oxides contained in the glass should be such that Na2O / (Li2O+MgO+CaO+SrO+BaO) is large, but if it is too large, it leads to a decrease in weather resistance, so the ratio of these is in the range of 0.5 to 3. Furthermore, the ratio is preferably 0.5 to 2.5, and more preferably 0.7 to 2.

[0080] Furthermore, as the near-infrared absorbing glass, chemically strengthened glass may be used, which is obtained by exchanging alkali metal ions having a small ionic radius (e.g., Li ions, Na ions) present on the main surface of the glass plate with alkali ions having a larger ionic radius (e.g., Na ions or K ions for Li ions, and K ions for Na ions) by ion exchange at a temperature equal to or lower than the glass transition point.

[0081] The near-infrared absorbing glass preferably has a thickness of 0.5 mm or less, more preferably 0.3 mm or less, from the viewpoint of reducing the height of the camera module, and preferably has a thickness of 0.15 mm or more, from the viewpoint of element strength.

[0082] <Resin film> The resin film preferably satisfies all of the following spectral properties (iv-1) to (iv-5). (iv-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 93% (iv-2) Maximum internal transmittance T at wavelengths of 450 to 600 nm 450-600MAX More than 95% (iv-3) Internal transmittance T at a wavelength of 450 nm 450 Over 86% (iv-4) The shortest wavelength at which the internal transmittance is 50% in the spectral transmittance curve of wavelengths from 650 to 900 nm is IR50 (S)The longest wavelength is IR50 (L) When IR50 (L) -IR50 (S) ≧90nm (iv-5) Minimum internal transmittance T at wavelengths of 700 to 800 nm 700-800MIN is less than 10%

[0083] Satisfying the spectral characteristics (iv-1) and (iv-2) means that the transmittance in the visible light region of 450 to 600 nm is excellent. T 450-600AVE is preferably 93.5% or more, more preferably 94% or more. T 450-600MAX is preferably 96% or more, more preferably 97% or more.

[0084] Satisfying the spectral characteristic (iv-3) means that the transmittance in the blue light region is excellent. T 450 is preferably 88% or more, more preferably 89% or more.

[0085] By satisfying the spectral characteristic (iv-4), it is possible to block a wide range of near-infrared light around 700 nm. IR50 (L) -IR50 (S) is preferably 95 nm or more, more preferably 100 nm or more.

[0086] Satisfying the spectral characteristic (iv-5) means that the film has excellent light-blocking properties in the near-infrared region of 700 to 800 nm. T 700-800MIN is preferably 8% or less, more preferably 7% or less.

[0087] It is preferable that the resin film further satisfies the following spectral properties (iv-6) to (iv-7). (iv-6) Wavelength IR50 at which internal transmittance is 50% (S) is in the range of 650-700 nm (iv-7) Wavelength IR50 at which internal transmittance is 50% (L)is in the range of 740-850 nm By satisfying the spectral characteristics (iv-6) to (iv-7), it is possible to efficiently block the near-infrared light region around 700 nm. IR50 (S) is preferably 650 to 690 nm, more preferably 660 to 690 nm. IR50 (L) is preferably 750 to 830 nm, more preferably 760 to 830 nm.

[0088] It is preferable that the resin film further satisfies the following spectral characteristic (iv-8). (iv-8) Average internal transmittance T at wavelength 700~800nm 700-800AVE is 30% or less Satisfying the spectral characteristic (iv-8) means that the film has excellent light-blocking properties in the near-infrared region of 700 to 800 nm. T 700-800AVE is preferably 28% or less, more preferably 25% or less.

[0089] It is preferable that the resin film further satisfies the following spectral properties (iv-9) to (iv-11). (iv-9) The wavelength UV50 at which the internal transmittance is 50% is in the range of 400 to 440 nm. (iv-10) Average internal transmittance T at wavelength 370~400nm 370-400AVE is less than 3% (iv-11) Maximum internal transmittance T at wavelengths of 370 to 400 nm 370-400MAX is less than 5% Satisfying the spectral properties (iv-9) to (iv-11) means that the film has excellent light-blocking properties in the near-ultraviolet region of 370 to 400 nm. UV50 is preferably in the range of 400 to 430 nm, more preferably 410 to 430 nm. T 370-400AVE is preferably 2% or less, more preferably 1% or less. T 370-400MAX is preferably 4.8% or less, more preferably 4.6% or less.

[0090] The resin film in the present invention contains a dye (NIR1) having a maximum absorption wavelength in the range of 680 to 740 nm, and as shown in the above characteristics (iv-4) and (iv-5), it is particularly excellent in wide light shielding properties in the near-infrared light region around 700 nm. Thereby, the near-infrared light region around 700 nm where the light shielding property of the infrared absorbing glass is slightly weak can be shielded by the absorption characteristics of the dye.

[0091] The dye (NIR1) has a maximum absorption wavelength in the range of 680 to 740 nm, preferably 700 to 730 nm, in the resin. Here, the resin refers to the resin constituting the resin film. As the NIR dye, it may consist of one kind of compound or may contain two or more kinds of compounds. Here, the resin film in the present invention preferably further contains other near-infrared absorbing dyes having different maximum absorption wavelengths in addition to the dye (NIR1). Thereby, the resin film can obtain wide light shielding properties in the near-infrared light region around 700 nm, and the characteristic (iv-4) is easily obtained. As the other near-infrared absorbing dye, a dye (NIR2) having a maximum absorption wavelength in the resin that is 30 to 130 nm larger than that of the dye (NIR1) is preferable. Further, the maximum absorption wavelength of the dye (NIR2) is preferably 740 to 870 nm.

[0092] As the dye (NIR1), a squarylium compound is preferable from the viewpoints of the region of the maximum absorption wavelength, the transmittance in the visible light region, the solubility in the resin, and the durability. The maximum absorption wavelength of the squarylium compound which is the dye (NIR1) is preferably 680 to 740 nm. As the dye (NIR2), a squarylium compound and a cyanine compound are preferable from the viewpoints of the region of the maximum absorption wavelength, the transmittance in the visible light region, the solubility in the resin, and the durability. Further, the maximum absorption wavelength of the squarylium compound which is the dye (NIR2) is preferably 740 to 770 nm. The maximum absorption wavelength of the cyanine compound which is the dye (NIR2) is preferably 740 to 860 nm.

[0093] <NIR1: Squarylium compound> When two or more identical symbols are present in a squarylium compound, those symbols may be the same or different. The same applies to cyanine compounds.

[0094] <Squarylium Compounds (I)>

[0095] [ka]

[0096] However, the symbols in the above formula are as follows: R 24 and R 26 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms, -NR 27 R 28 (R 27 and R 28 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or -C(=O)-R 29 (R 29 represents a hydrogen atom, a halogen atom, a hydroxyl group, a hydrocarbon group having 1 to 25 carbon atoms which may have a substituent and which may contain an unsaturated bond between carbon atoms, an oxygen atom, or a saturated or unsaturated ring structure), -NHR 30 , or -SO2-R 30 (R 30 represents a hydrocarbon group having 1 to 25 carbon atoms, each of which may have one or more hydrogen atoms substituted with a halogen atom, a hydroxyl group, a carboxyl group, a sulfo group, or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms), or a group represented by the following formula (S): 41 , R 42 are independently a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 10 carbon atoms. k is 2 or 3.

[0097] [ka]

[0098] R 21 and R 22 , R 22 and R 25 , and R 21 and R 23 may be linked to each other to form, together with the nitrogen atom, 5- or 6-membered heterocycles A, B, and C, respectively. R when heterocycle A is formed 21 and R 22 represents a divalent group -Q- to which they are bonded, which is an alkylene group or alkyleneoxy group in which a hydrogen atom may be substituted with an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms which may have a substituent. R when heterocycle B is formed 22 and R 25 and R when heterocycle C is formed. 21 and R 23 are the divalent groups -X 1 -Y 1 - and -X 2 -Y 2 -(The side that is bonded to nitrogen is X 1 and X 2 ) as X 1 and X 2 are groups represented by the following formula (1x) or (2x), and Y 1 and Y 2 are each a group selected from the following formulas (1y) to (5y): 1 and X 2 are groups represented by the following formula (2x), Y 1 and Y 2 may each be a single bond, in which case there may be an oxygen atom between the carbon atoms.

[0099] [ka]

[0100] In formula (1x), four Z's each independently represent a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, or -NR 38 R 39 (R 38 and R 39 R each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 31 ~R 36 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 37 represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. R 27 , R 28 , R 29 , R 31 ~R 37 , R when not forming a heterocycle 21 ~R 23 , and R 25 may be bonded to any other of these to form a 5- or 6-membered ring. 31 and R 36 , R 31 and R 37 may be directly bonded. When a heterocyclic ring is not formed, R 21 , R 22 , R 23 and R 25 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, or an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms.

[0101] Examples of compound (I) include compounds represented by any of formulas (I-1) to (I-3). From the viewpoints of solubility in resin, heat resistance and light resistance in resin, and visible light transmittance of a resin layer containing the compound, the compound represented by formula (I-1) is particularly preferred.

[0102] [ka]

[0103] The symbols in formulae (I-1) to (I-3) have the same definitions as those of the same symbols in formula (I), and the preferred embodiments are also the same.

[0104] In compound (I-1), X 1 As the group (2x), the group (2x) is preferred. 1 is preferably a single bond or a group (1y). 31 ~R 36 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group. 1 -X 1 Specific examples of - include divalent organic groups represented by formulas (11-1) to (12-3).

[0105] -C(CH3)2-CH(CH3)- …(11-1) -C(CH3)2-CH2- …(11-2) -C(CH3)2-CH(C2H5)- …(11-3) -C(CH3)2-C(CH3)(nC3H7)- …(11-4) -C(CH3)2-CH2-CH2- …(12-1) -C(CH3)2-CH2-CH(CH3)- …(12-2) -C(CH3)2-CH(CH3)-CH2- …(12-3)

[0106] In addition, in compound (I-1), R 21 are more preferably independently a group represented by formula (4-1) or (4-2) from the viewpoints of solubility, heat resistance, and the steepness of the change in the spectral transmittance curve near the boundary between the visible region and the near-infrared region.

[0107] [ka]

[0108] In formula (4-1) and formula (4-2), R71 ~R 75 are independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0109] In compound (I-1), R 24 Ha-NR 27 R 28 -NR is preferred. 27 R 28 From the viewpoint of solubility in resins and coating solvents, -NH-C(=O)-R 29 or -NH-SO2-R 30 is preferred.

[0110] In compound (I-1), R 24 -NH-C(=O)-R 29 The compound is shown in formula (I-11).

[0111] [ka]

[0112] R 23 and R 26 are each independently preferably a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrogen atom.

[0113] R 29 The substituent is preferably an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 10 carbon atoms which may have a substituent, or an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms. Examples of the substituent include a hydroxyl group, a carboxy group, a sulfo group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an acyloxy group having 1 to 6 carbon atoms.

[0114] R 29Examples of the group include a linear, branched or cyclic alkyl group having 1 to 17 carbon atoms, a phenyl group optionally substituted with an alkoxy group having 1 to 6 carbon atoms, and an aralkyl group having 7 to 18 carbon atoms which may have an oxygen atom between carbon atoms.

[0115] R 29 Examples of the group also preferably include a hydrocarbon group having at least one branch and 5 to 25 carbon atoms, in which one or more hydrogen atoms may be independently substituted with a hydroxyl group, a carboxyl group, a sulfo group or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms.

[0116] More specifically, examples of the compound (I-11) include the compounds shown in the following table. In addition, for the compounds shown in the following table, the meanings of the respective symbols are the same on the left and right of the squarylium skeleton.

[0117] [Table 1]

[0118] Among these, as the compound (I-11), compounds (1-11-1) to (1-11-12), and compounds (1-11-17) to (1-11-28) are preferable from the viewpoints of solubility in resin, maximum absorption wavelength, light resistance, heat resistance, and high absorbance. Particularly, compounds (1-11-1) to (1-11-12) are preferable from the viewpoints of light resistance and heat resistance. Since the light shielding property in the ultraviolet region by the dielectric multilayer film in the configuration of the present invention is gentle, the light resistance of the dye is particularly important.

[0119] <NIR2: Squarylium compound> The squarylium compound as the dye (NIR2) is preferably a compound represented by the following formula (II).

[0120] <Squarylium compound (II)>

[0121] [Chemical formula]

[0122] However, the symbols in the above formula are as follows: Each ring Z is independently a 5- or 6-membered ring having 0 to 3 heteroatoms in the ring, and the hydrogen atoms in ring Z may be substituted. R 1 and R 2 , R 2 and R 3 , and R 1 The carbon atoms or heteroatoms constituting ring Z may be bonded to each other to form heterocycles A1, B1, and C1 together with the nitrogen atom, respectively, and in this case, the hydrogen atoms of heterocycles A1, B1, and C1 may be substituted. 1 and R 2 R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group which may contain an unsaturated bond between carbon atoms, a heteroatom, or a saturated or unsaturated ring structure and which may have a substituent. 4 and R when no heterocycle is formed. 3 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group which may contain a heteroatom between carbon atoms and which may have a substituent.

[0123] Examples of compound (II) include compounds represented by any of formulas (II-1) to (II-3). From the viewpoints of solubility in resins and visible light transmittance in resins, the compound represented by formula (II-3) is particularly preferred.

[0124] [ka]

[0125] In formula (II-1) and formula (II-2), R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent, and R3 ~R 6 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms which may have a substituent.

[0126] In formula (II-3), R 1 , R 4 , and R 9 ~R 12 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent, and R 7 and R 8 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may have a substituent.

[0127] R in Compound (II-1) and Compound (II-2) 1 and R 2 are each independently preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 7 to 15 carbon atoms, from the viewpoints of solubility in resin, visible light transmittance, etc., and R 1 and R 2 More preferably, at least one of R is a branched alkyl group having 7 to 15 carbon atoms, 1 and R 2 It is particularly preferable that both of the groups are alkyl groups having a branched chain and having 8 to 15 carbon atoms.

[0128] R in compound (II-3) 1 From the viewpoints of solubility in a transparent resin, visible light transmittance, etc., each of the groups is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an ethyl group or an isopropyl group.

[0129] R 4 From the viewpoints of visible light transmittance and ease of synthesis, is preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom. R 7 and R 8 are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and more preferably a hydrogen atom, a halogen atom, or a methyl group.

[0130] R 9 ~R 12 are preferably independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom. -CR 9 R 10 -CR 11 R 12 Examples of - include divalent organic groups represented by the following groups (13-1) to (13-5). -CH(CH3)-C(CH3)2- …(13-1) -C(CH3)2-CH(CH3)- …(13-2) -C(CH3)2-CH2- …(13-3) -C(CH3)2-CH(C2H5)- …(13-4) -CH(CH3)-C(CH3)(CH2-CH(CH3)2)-…(13-5)

[0131] More specifically, examples of compound (II-3) include the compounds shown in the following table: In the compounds shown in the following table, the symbols on the left and right of the squarylium skeleton have the same meaning.

[0132] [Table 2]

[0133] Of these, compounds (II-3-1) to (II-3-4) are preferred as compound (II-3) from the viewpoints of solubility in resin, high absorption coefficient, light resistance, and heat resistance.

[0134] Compounds (I) and (II) can be produced by known methods. Compound (I) can be produced by the methods described in U.S. Pat. No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and WO 2014 / 088063. Compound (II) can be produced by the method described in WO 2017 / 135359.

[0135] <NIR2: Cyanine compound> As the cyanine compound which is the pigment (NIR2), the compounds represented by the following formula (III) and formula (IV) are preferable.

[0136] <Cyanine compounds (III), (IV)>

[0137]

Chemical formula

[0138] However, the symbols in the above formula are as follows. R 101 ~R 109 and R 121 ~R 131 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. R 110 ~R 114 and R 132 ~R 136 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms. X - represents a monovalent anion. n1 and n2 are 0 or 1. -(CH2) n1 -containing carbocyclic ring, and the hydrogen atom bonded to the -(CH2) n2 -containing carbocyclic ring may be substituted with a halogen atom, an alkyl group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms.

[0139] In the above, the alkyl group (including the alkyl group of an alkoxy group) may be linear or may have a branched structure or a saturated ring structure. The aryl group refers to a group that bonds via a carbon atom constituting an aromatic ring of an aromatic compound, such as a benzene ring, naphthalene ring, biphenyl, furan ring, thiophene ring, or pyrrole ring. Examples of the substituent in the alkyl group or alkoxy group having 1 to 15 carbon atoms or the aryl group having 5 to 20 carbon atoms that may have a substituent include a halogen atom and an alkoxy group having 1 to 10 carbon atoms.

[0140] In formula (III) and formula (IV), R 101 and R 121 is preferably an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms, and more preferably a branched alkyl group having 1 to 15 carbon atoms from the viewpoint of maintaining high visible light transmittance in the resin.

[0141] In formula (III) and formula (IV), R 102 ~R 105 , R 108 , R 109 , R 122 ~R 127 , R 130 and R 131 are each independently preferably a hydrogen atom, an alkyl or alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0142] In formula (III) and formula (IV), R 110 ~R 114 and R 132 ~R 136 are each independently preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0143] R 106 , R 107 , R 128 and R 129are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 106 and R 107 , R 128 and R 129 are preferably the same group.

[0144] X - As for I - , BF4 - , PF6 - , ClO4 - , anions represented by formula (X1) and (X2), etc., and preferably BF4 - , or PF6 - is.

[0145] [ka]

[0146] In the following description, R 101 ~R 114 The part excluding is also called skeleton (III). The same applies to dye (IV).

[0147] In formula (III), a compound in which n1 is 1 is shown in formula (III-1) below, and a compound in which n1 is 0 is shown in formula (III-2) below.

[0148] [ka]

[0149] In formula (III-1) and formula (III-2), R 101 ~R 114 and X - is the same as in formula (III). 115 ~R 120R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 115 ~R 120 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 115 ~R 120 are preferably the same group.

[0150] In formula (IV), a compound in which n2 is 1 is shown in formula (IV-1) below, and a compound in which n2 is 0 is shown in formula (IV-2) below.

[0151] [ka]

[0152] In formula (IV-1) and formula (IV-2), R 121 ~R 136 and X - is the same as in formula (IV). 137 ~R 142 R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 137 ~R 142 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 137 ~R 142 are preferably the same group.

[0153] More specifically, the compounds represented by formula (III-1), formula (III-2), formula (IV-1), and formula (IV-2) each include compounds in which the atom or group bonded to each skeleton is an atom or group shown in the table below. In all of the compounds shown in the table below, R 101 ~R 109 are the same on both sides of the formula. In all compounds shown in the table below, R 121 ~R 131 is identical on both sides of the equation.

[0154] R in the table below 110 -R 114 and R in the table below 132 -R 136 indicates the atom or group bonded to the central benzene ring of each formula, and when all five are hydrogen atoms, it is written as "H". 110 -R 114 If one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is described. For example, "R 112 -C(CH3)3" is R 112 is -C(CH3)3, and the rest are hydrogen atoms. 132 -R 136 The same is true for .

[0155] R in the table below 115 -R 120 and R in the table below 137 -R 142 represents an atom or group bonded to the central cyclohexane ring in formula (III-1) or formula (IV-1), and when all six are hydrogen atoms, it is written as "H". 115 -R 120 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 142 The same is true for .

[0156] R in the table below 115 -R 118 and R in the table below 137 -R140 represents an atom or group bonded to the central cyclopentane ring in formula (III-2) or formula (IV-2), and when all four are hydrogen atoms, it is written as "H". 115 -R 118 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 140 The same is true for .

[0157] [Table 3]

[0158] Among these, the dyes (III-1) are preferably the dyes (III-1-1) to (III-1-12) in terms of heat resistance, light resistance, solubility in resins, and ease of synthesis.

[0159] [Table 4]

[0160] Among these, the dyes (III-2-1) to (III-2-12) are preferred as the dye (III-2) from the viewpoints of heat resistance, light resistance, solubility in resins, and ease of synthesis.

[0161] [Table 5]

[0162] Among these, dyes (IV-1) such as dyes (IV-1-1) to (IV-1-12) are preferred as dye (IV-1) from the viewpoints of heat resistance, light resistance, solubility in resins, and ease of synthesis.

[0163] [Table 6]

[0164] Among these, as the pigment (IV-2), pigments (IV-2-1) to (IV-2-15) etc. are preferable from the viewpoints of heat resistance, light resistance, solubility in resins, and simplicity of synthesis.

[0165] The pigments (III) and pigments (IV) can be produced, for example, by the methods described in Dyes and pigments 73(2007) 344-352 and J.Heterocyclic chem,42,959(2005).

[0166] The content of the NIR pigment in the resin film is preferably 0.1 to 25 parts by mass, more preferably 0.3 to 15 parts by mass with respect to 100 parts by mass of the resin. When combining two or more kinds of compounds, the above content is the total of each compound. When the pigments (NIR1) and the pigment (NIR2) are used in combination, the content of the pigment (NIR1) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin, and the content of the pigment (NIR2) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin.

[0167] In addition to the pigments (NIR1) and the pigment (NIR2), the resin film may contain other near-infrared absorbing pigments. As other near-infrared absorbing pigments, from the viewpoint of being able to block light in a wide range in the near-infrared region, pigments having a maximum absorption wavelength larger than that of the pigment (NIR2) are preferable, and specifically, cyanine compounds, diimonium compounds, etc. can be mentioned.

[0168] <UV pigment> In addition to the above NIR pigments, the resin film may contain other pigments. As other pigments, pigments (UV) having a maximum absorption wavelength of 370 to 440 nm in the resin are preferable. Thereby, the near-ultraviolet region can be efficiently blocked.

[0169] Examples of the dye (UV) include oxazole dyes, merocyanine dyes, cyanine dyes, naphthalimide dyes, oxadiazole dyes, oxazine dyes, oxazolidine dyes, naphthalic acid dyes, styryl dyes, anthracene dyes, cyclic carbonyl dyes, and triazole dyes. Among these, merocyanine dyes are particularly preferred. One type may be used alone, or two or more types may be used in combination.

[0170] As the dye (UV), a merocyanine dye represented by the following formula (M) is particularly preferred.

[0171] [ka]

[0172] The symbols in formula (M) are as follows:

[0173] R 1 represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. The substituent is preferably an alkoxy group, an acyl group, an acyloxy group, a cyano group, a dialkylamino group, or a chlorine atom. The alkoxy group, acyl group, acyloxy group, and dialkylamino group preferably have 1 to 6 carbon atoms.

[0174] Unsubstituted R 1 Specifically, preferred are alkyl groups having 1 to 12 carbon atoms in which some of the hydrogen atoms may be substituted with an aliphatic ring, an aromatic ring, or an alkenyl group; cycloalkyl groups having 3 to 8 carbon atoms in which some of the hydrogen atoms may be substituted with an aromatic ring, an alkyl group, or an alkenyl group; and aryl groups having 6 to 12 carbon atoms in which some of the hydrogen atoms may be substituted with an aliphatic ring, an alkyl group, or an alkenyl group.

[0175] R 1 When is an unsubstituted alkyl group, the alkyl group may be linear or branched, and more preferably has 1 to 6 carbon atoms.

[0176] R1 is an alkyl group having 1 to 12 carbon atoms in which some of the hydrogen atoms are substituted with an aliphatic ring, an aromatic ring, or an alkenyl group, an alkyl group having 1 to 4 carbon atoms having a cycloalkyl group having 3 to 6 carbon atoms, or an alkyl group having 1 to 4 carbon atoms substituted with a phenyl group is more preferred, and an alkyl group having 1 or 2 carbon atoms substituted with a phenyl group is particularly preferred. Note that an alkyl group substituted with an alkenyl group means an alkenyl group as a whole that does not have an unsaturated bond between the 1- and 2-positions, such as an allyl group or a 3-butenyl group.

[0177] Preferred R 1 is an alkyl group having 1 to 6 carbon atoms in which some of the hydrogen atoms may be substituted with a cycloalkyl group or a phenyl group. 1 is an alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group.

[0178] R 2 ~R 5 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The alkyl group and alkoxy group preferably have 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms.

[0179] R 2 and R 3 At least one of R is preferably an alkyl group, and more preferably both are alkyl groups. 2 and R 3 When R is not an alkyl group, a hydrogen atom is more preferred. 2 and R 3 In any case, an alkyl group having 1 to 6 carbon atoms is particularly preferred.

[0180] R 4 and R 5 At least one of R is preferably a hydrogen atom, and more preferably both are hydrogen atoms. 4 or R 5When is not a hydrogen atom, it is preferably an alkyl group having 1 to 6 carbon atoms.

[0181] Y is R 6 and R 7 represents a methylene group or an oxygen atom substituted with R 6 and R 7 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0182] X represents any one of the divalent groups represented by the following formulas (X1) to (X5).

[0183] [ka]

[0184] R 8 and R 9 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and R 10 ~R 19 each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. R 8 ~R 19 The substituents of R 1 The same substituents as those in R are mentioned, and the preferred embodiments are also the same. 8 ~R 19 is a hydrocarbon group having no substituents, R 1 The same aspects as above can be mentioned.

[0185] In formula (X1), R 8 and R 9 may be different groups, but are preferably the same group. 8 and R 9 When is an unsubstituted alkyl group, it may be linear or branched, and more preferably has 1 to 6 carbon atoms.

[0186] Preferred R8 and R 9 Each of R is an alkyl group having 1 to 6 carbon atoms in which some of the hydrogen atoms may be substituted with a cycloalkyl group or a phenyl group. 8 and R 9 are all alkyl groups having 1 to 6 carbon atoms, and specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group.

[0187] In formula (X2), R 10 and R 11 are more preferably alkyl groups having 1 to 6 carbon atoms, and it is particularly preferred that they are the same alkyl groups.

[0188] In formula (X3), R 12 and R 15 are preferably both hydrogen atoms or unsubstituted alkyl groups having 1 to 6 carbon atoms. 13 and R 14 are preferably all hydrogen atoms or all alkyl groups having 1 to 6 carbon atoms.

[0189] In formula (X4), two groups R bonded to the same carbon atom 16 and R 17 and R 18 and R 19 are preferably all hydrogen atoms or all alkyl groups having 1 to 6 carbon atoms.

[0190] The compound (M) can be produced by a known method.

[0191] The content of the dye (UV) in the resin film is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the resin. If the content is within this range, the resin properties are less likely to deteriorate.

[0192] <Base material composition> The substrate in this filter is a composite substrate in which a resin film is laminated on at least one main surface of near-infrared absorbing glass.

[0193] The resin is not limited as long as it is a transparent resin, and one or more transparent resins selected from polyester resin, acrylic resin, epoxy resin, enethiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyparaphenylene resin, polyarylene ether phosphine oxide resin, polyamide resin, polyimide resin, polyamideimide resin, polyolefin resin, cyclic olefin resin, polyurethane resin, polystyrene resin, etc. These resins may be used alone or in combination of two or more. From the viewpoint of the spectral characteristics, glass transition temperature (Tg) and adhesiveness of the resin film, one or more resins selected from polyimide resin, polycarbonate resin, polyester resin and acrylic resin are preferred.

[0194] When a plurality of compounds are used as the NIR dye or other dyes, they may be contained in the same resin film, or may be contained in separate resin films.

[0195] The resin film can be formed by dissolving or dispersing the dye, the resin or the raw material components of the resin, and the components that are mixed as needed in a solvent to prepare a coating solution, then coating the coating solution on a support, drying it, and then curing it as needed.The support in this case can be the near-infrared absorbing glass used in this filter, or a peelable support that is used only when forming the resin film.In addition, the solvent can be any dispersion medium that can be stably dispersed or a solvent that can be dissolved.

[0196] The coating liquid may also contain a surfactant to prevent voids caused by microbubbles, depressions caused by the adhesion of foreign matter, and repellency during the drying process. For example, the coating liquid can be applied by dip coating, cast coating, or spin coating. After the coating liquid is applied to a support, a resin film is formed by drying. When the coating liquid contains raw materials for a transparent resin, it is further subjected to a curing treatment such as thermal curing or photocuring.

[0197] The resin film can also be produced in a film form by extrusion molding. The resulting film-like resin film can be laminated on near-infrared absorbing glass and integrated by thermocompression bonding or the like to produce a substrate.

[0198] The optical filter may have one resin film layer or two or more resin films. When the optical filter has two or more resin films, the layers may have the same or different configurations.

[0199] The thickness of the resin film is 10 μm or less, preferably 5 μm or less, from the viewpoint of the in-plane film thickness distribution within the substrate after coating and the appearance quality, and is preferably 0.5 μm or more, from the viewpoint of achieving the desired spectral characteristics at an appropriate dye concentration. When the optical filter has two or more resin film layers, it is preferable that the total thickness of the resin film layers is within the above range.

[0200] The shape of the substrate is not particularly limited, and may be a block, plate, or film.

[0201] The filter may also include other components, such as a component (layer) that provides absorption by inorganic fine particles that control the transmission and absorption of light in a specific wavelength range. Specific examples of inorganic fine particles include ITO (indium tin oxide), ATO (antimony-doped tin oxide), cesium tungstate, and lanthanum boride. ITO fine particles and cesium tungstate fine particles have high transmittance for visible light and absorb light over a wide range of infrared wavelengths exceeding 1200 nm, and therefore can be used when blocking such infrared light is required.

[0202] As described above, this specification discloses the following optical filters and the like. [1] An optical filter comprising a substrate, a dielectric multilayer film 1 laminated as an outermost layer on one main surface side of the substrate, and a dielectric multilayer film 2 laminated as an outermost layer on the other main surface side of the substrate, the substrate comprises a near-infrared absorbing glass and a resin film having a thickness of 10 μm or less laminated on at least one main surface of the near-infrared absorbing glass, the resin film contains a resin and a dye (NIR1) having a maximum absorption wavelength in the resin at 680 to 740 nm; The optical filter satisfies all of the following spectral characteristics (i-1) to (i-14). (i-1) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 450-600(0deg)AVE Over 85% (i-2) In the spectral transmittance curve at an incident angle of 0 degrees, the maximum transmittance T 450-600(0deg)MAX Over 90% (i-3) The average transmittance T 450-600(0deg)AVE and the average transmittance T of the spectral transmittance curve for wavelengths from 450 to 600 nm at an incident angle of 50 degrees. 450-600(50deg)AVE The absolute difference between (i-4) In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance T at a wavelength of 450 nm 450(0deg) Over 80% (i-5) In the spectral transmittance curve at an incident angle of 0 degrees, the wavelength IR50 at which the transmittance is 50% (0deg) is in the range of 610-650 nm (i-6) The wavelength IR50 (0deg) In the spectral transmittance curve at an incident angle of 50 degrees, the wavelength at which the transmittance is 50% is IR50 (50deg) The absolute value of the difference is 10 nm or less (i-7) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 700-1000(0deg)AVE is less than 2% (i-8) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T 700-1000(50deg)AVE is less than 2% (i-9) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 1000-1200(0deg)AVE is less than 5% (i-10) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T 1000-1200(50deg)AVE is less than 5% (i-11) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 at a wavelength of 450 to 600 nm 450-600(5deg)MAX is less than 2% (i-12) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less (i-13) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 450 to 600 nm 450-600(5deg)MAX is less than 3% (i-14) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 in the wavelength range of 600 to 1200 nm 600-1200(5deg)MAX is 45% or less [2] The optical filter according to [1], which further satisfies the following spectral characteristics (i-15) to (i-18). (i-15) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 at a wavelength of 450 to 600 nm 450-600(50deg)MAX is 7% or less (i-16) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 600 to 1200 nm 600-1200(50deg)MAX is 45% or less (i-17) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 450 to 600 nm 450-600(50deg)MAX is 7% or less (i-18) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 600 to 1200 nm 600-1200(50deg)MAX is 45% or less [3] The optical filter according to [1] or [2], which further satisfies the following spectral characteristics (i-19) to (i-20). (i-19) Said transmittance T 450(0deg) / The maximum transmittance T 1000-1200(0deg)MAX ≧20 (i-20) Said transmittance T 450(0deg) / The maximum transmittance T 1000-1200(50deg)MAX ≧20 [4] The optical filter according to any one of [1] to [3], which further satisfies the following spectral characteristics (i-21) to (i-28). (i-21) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 450 to 700 nm 450-700(5deg)MAX is 7% or less (i-22) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 450 to 700 nm 450-700(50deg)MAX is 7% or less (i-23) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 in the wavelength range of 700 to 1200 nm 700-1200(5deg)MAX is 45% or less (i-24) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 in the wavelength range of 700 to 1200 nm 700-1200(50deg)MAX is 45% or less (i-25) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 450 to 700 nm 450-700(5deg)MAX is 7% or less (i-26) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 450 to 700 nm 450-700(50deg)MAX is 7% or less (i-27) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R2 at a wavelength of 700 to 1200 nm 700-1200(5deg)MAX is 45% or less (i-28) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 700 to 1200 nm 700-1200(50deg)MAX is 45% or less [5] The optical filter according to any one of [1] to [4], wherein the substrate satisfies all of the following spectral characteristics (ii-1) to (ii-7): (ii-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 84% (ii-2) Maximum internal transmittance T in the wavelength range of 450 to 600 nm 450-600MAX Over 90% (ii-3) Internal transmittance T at a wavelength of 450 nm 450 Over 80% (ii-4) The wavelength IR50 at which the internal transmittance is 50% is in the range of 610 to 650 nm. (ii-5) Average internal transmittance T at wavelength 750~1000nm 750-1000AVE is 1.5% or less (ii-6) Maximum internal transmittance T at wavelengths of 1000 to 1200 nm 1000-1200MAX is less than 5% (ii-7) The internal transmittance T 450 / The maximum internal transmittance T 1000-1200MAX ≧15 [6] The optical filter according to any one of [1] to [5], wherein the near-infrared absorbing glass satisfies all of the following spectral properties (iii-1) to (iii-6): (iii-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 90% (iii-2) Internal transmittance T at a wavelength of 450 nm 450 Over 92% (iii-3) The wavelength IR50 at which the internal transmittance is 50% is in the range of 625 to 650 nm (iii-4) Average internal transmittance T at wavelength 750~1000nm 750-1000AVE is 2.5% or less (iii-5) Maximum internal transmittance T in the wavelength range of 1000 to 1200 nm 1000-1200MAX is less than 5% (iii-6) The internal transmittance T 450 / The maximum internal transmittance T 1000-1200MAX ≧10 [7] The optical filter according to any one of [1] to [6], wherein the resin film satisfies all of the following spectral characteristics (iv-1) to (iv-5): (iv-1) Average internal transmittance T at wavelength 450~600nm 450-600AVE Over 93% (iv-2) Maximum internal transmittance T at wavelengths of 450 to 600 nm 450-600MAX More than 95% (iv-3) Internal transmittance T at a wavelength of 450 nm 450 Over 86% (iv-4) The shortest wavelength at which the internal transmittance is 50% in the spectral transmittance curve of wavelengths from 650 to 900 nm is IR50 (S) The longest wavelength is IR50 (L) When IR50 (L) -IR50 (S) ≧90nm (iv-5) Minimum internal transmittance T at wavelengths of 700 to 800 nm 700-800MIN is less than 10% [8] The resin film further contains a dye (NIR2), The optical filter according to any one of [1] to [7], wherein the dye (NIR2) has a maximum absorption wavelength in the resin that is 30 to 130 nm longer than the maximum absorption wavelength of the dye (NIR1) in the resin. [9] The resin film further contains a dye (UV) having a maximum absorption wavelength in the resin of 360 to 440 nm; The optical filter according to any one of [1] to [8], further satisfying the following spectral characteristics (i-29) to (i-33). (i-29) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T 360-400(0deg)AVE is less than 2% (i-30) The average transmittance T of the spectral transmittance curve at an incident angle of 50 degrees from 360 to 4000 nm 360-400(50deg)AVE is less than 2% (i-31) In the spectral transmittance curve at an incident angle of 0 degrees, the wavelength at which the transmittance is 50% is UV50 (0deg) is in the range of 400-440 nm (i-32) In the spectral transmittance curve at an incident angle of 50 degrees, the wavelength at which the transmittance is 50% is UV50 (50deg) is in the range of 400-440 nm (i-33) The wavelength UV50 (0deg) and the wavelength UV50 (50deg) The absolute difference is 3 nm or less

[10] The resin film contains at least one of a squarylium compound and a cyanine compound as a dye (NIR1) having a maximum absorption wavelength in the range of 680 to 740 nm in the resin; The optical filter according to any one of [1] to [9], further comprising at least one of a squarylium compound and a cyanine compound as a dye (NIR2) whose maximum absorption wavelength in the resin is 30 to 130 nm longer than the maximum absorption wavelength of the dye (NIR1) in the resin.

[11] An imaging device equipped with the optical filter according to any one of [1] to

[10] . [Example]

[0203] Next, the present invention will be explained more specifically with reference to examples. Each spectral characteristic was measured using an ultraviolet-visible spectrophotometer (UH-4150, manufactured by Hitachi High-Technologies Corporation). Unless the angle of incidence is specifically stated, the spectral characteristics are values ​​measured at an angle of incidence of 0° (perpendicular to the main surface of the optical filter).

[0204] The dyes used in each example are as follows: Compound 1 (squarylium compound): Synthesized based on WO 2014 / 088063 and WO 2016 / 133099. Compound 2 (merocyanine compound): Synthesized based on the specification of German Patent Publication No. 10109243. Compound 3 (squarylium compound): Synthesized based on WO 2017 / 135359. Compound 4 (cyanine compound): Synthesized according to the method described in Dyes and Pigments, 73, 344-352 (2007). Compound 5 (cyanine compound): Synthesized according to the method described in Dyes and Pigments, 73, 344-352 (2007). Compound 6 (diimmonium compound): Synthesized based on the method described in Japanese Patent No. 4800769.

[0205] [ka]

[0206] <Spectral characteristics of dyes in resin> A polyimide resin ("C3G30G" (trade name) manufactured by Mitsubishi Gas Chemical Company, Inc., refractive index 1.59) was dissolved in γ-butyrolactone (GBL):cyclohexanone = 1:1 (mass ratio) to prepare a polyimide resin solution with a resin concentration of 8.5 mass %. Each of the dyes of Compounds 1 to 6 was added to the resin solution at a concentration of 7.5 parts by mass per 100 parts by mass of resin, and the resulting solution was stirred and dissolved for 2 hours at 50° C. The resulting coating solution was applied to alkali glass (SCHOTT, D263 glass, thickness 0.2 mm) by spin coating to form a coating film with a thickness of approximately 1.0 μm. The spectral transmittance curve of the obtained coating film was measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. The following table shows the spectral properties of each of the above compounds 1 to 6 in a polyimide resin. The spectral properties shown in the table were evaluated using internal transmittance to avoid the influence of reflection at the air interface and the glass interface.

[0207] [Table 7]

[0208] <Spectral characteristics of near-infrared absorbing glass> As the near-infrared absorbing glass, phosphate glass (manufactured by AGC, SP50T) was prepared. The spectral transmittance curve of the near-infrared absorbing glass was measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From the obtained spectral characteristics data, the average internal transmittance T 450-600AVE , maximum internal transmittance T450-600MAX , internal transmittance T at a wavelength of 450 nm 450 , the wavelength at which the internal transmittance is 50%, IR50, the average internal transmittance T for wavelengths from 750 to 1000 nm 750-1000AVE , maximum internal transmittance T in the wavelength range of 1000 to 1200 nm 1000-1200MAX , internal transmittance T 450 / Maximum internal transmittance T 1000-1200MAX , was calculated. The results are shown in the table below. The spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflection at the air interface and the glass interface. FIG. 3 shows the spectral transmittance curve of the near-infrared absorbing glass.

[0209] [Table 8]

[0210] As shown above, it is clear that the near-infrared absorbing glass used has high transmittance in the visible light region and is excellent in light blocking properties in the near-infrared region.

[0211] <Examples 1-1 to 1-5: Spectral characteristics of resin films> A coating solution was obtained by mixing any one of the dyes from Compounds 1 to 6 at the concentrations shown in the table below with a polyimide resin solution prepared in the same manner as when calculating the spectral properties of the above compounds, and stirring and dissolving the mixture at 50° C. for 2 hours. The resulting coating solution was applied to alkaline glass (SCHOTT, D263 glass, thickness 0.2 mm) by spin coating to form a resin film with a thickness of 3.0 μm. The spectral transmittance curve of the obtained resin film was measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From the obtained spectral characteristics data, the average internal transmittance T 450-600AVE , maximum internal transmittance T in the range of 450 to 600 nm 450-600MAX , internal transmittance T at 450 nm 450 IR50 is the shortest wavelength at which the internal transmittance is 50% in the spectral transmittance curve of wavelengths from 650 to 900 nm. (S) and the longest wavelength IR50(L) The difference between the average internal transmittance T 700-800AVE , minimum internal transmittance T 700-800MIN , was calculated. The results are shown in the table below. The spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflection at the air interface and the glass interface. The spectral transmittance curve of the resin film of Example 1-1 is shown in FIG. Examples 1-1 to 1-5 are reference examples.

[0212] [Table 9]

[0213] <Examples 2-1 to 2-5: Spectral characteristics of substrates> A coating solution was obtained by mixing any one of the dyes of Compounds 1 to 6 at the concentrations shown in the table below with a polyimide resin solution prepared in the same manner as when calculating the spectral properties of the above compounds, and stirring and dissolving the mixture at 50° C. for 2 hours. The resulting coating solution was applied by spin coating to a 0.28 nm thick phosphate glass (near-infrared absorbing glass, manufactured by AGC, SP50T) to form a 3.0 μm thick resin film. The spectral transmittance curve of the obtained resin film was measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From the obtained spectral characteristics data, the average internal transmittance T 450-600AVE , maximum internal transmittance T 450-600MAX , internal transmittance T at 450 nm 450 , the wavelength at which the internal transmittance is 50%, IR50, the average internal transmittance T for wavelengths from 750 to 1000 nm 750-1000AVE , maximum internal transmittance T in the wavelength range of 1000 to 1200 nm 1000-1200MAX , internal transmittance T 450 / Maximum internal transmittance T 1000-1200MAX , was calculated. The results are shown in the table below. The spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflection at the air interface and the glass interface. The spectral transmittance curve of the substrate of Example 2-1 is shown in FIG. Examples 2-1 to 2-5 are reference examples.

[0214] [Table 10]

[0215] From the above results, it can be seen that by combining glass with excellent near-infrared absorption and visible light transmittance with a dye that deeply absorbs around 700 to 800 nm and has high visible light transmittance, the spectral characteristics of the optical filter can be almost guaranteed by the absorption characteristics of the substrate alone. In particular, the substrate in the present invention has a ratio of visible light transmittance to near-infrared light transmittance (T 450 / T 1000-1200MAX ) is high, it has both visible light transmittance and near-infrared blocking properties.

[0216] <Examples 3-1 to 3-5: Spectral characteristics of dielectric multilayer films> A dielectric multilayer film was formed by alternately depositing TiO2 and SiO2 on the surface of an alkali glass (SCHOTT, D263 glass, thickness 0.28 mm). The spectral transmittance curve of the obtained dielectric single / multilayer film was measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From the obtained spectral characteristics data, the minimum transmittance T 450-600(0deg)MIN , incident angle 50 degrees, minimum transmittance T at wavelength 450-600nm 450-600(50deg)MIN , incident angle 0 degrees, minimum transmittance T at wavelengths of 600 to 1200 nm 600-1200(0deg)MIN , incident angle 50 degrees, minimum transmittance T at wavelengths of 600 to 1200 nm 600-1200(50deg)MIN was calculated. The results are shown in the table below. Examples 3-1 to 3-5 are reference examples.

[0217] [Table 11]

[0218] From the above results, the dielectric multilayer films of Examples 3-1 to 3-4 have high visible light transmittance, little light blocking in the near-infrared region, and little spectral change in the visible region even at high incident angles.The dielectric multilayer film of Example 3-5 has high light blocking in the near-infrared region and a large spectral change in the visible region at high incident angles.

[0219] <Examples 4-1 to 4-8: Spectral characteristics of optical filters> For an optical film having a substrate having the configuration of any one of Examples 2-1 to 2-4 and a dielectric multilayer film (anti-reflection film) having the configuration of any one of Examples 3-1 to 3-5 on both sides of the substrate, the spectral transmittance curves at incident angles of 0 degrees and 50 degrees and the spectral reflectance curves at incident angles of 5 degrees and 50 degrees in the wavelength range of 350 to 1200 nm were measured using a UV-visible spectrophotometer. The optical filter was configured as follows: dielectric multilayer film 1 (front surface) / near-infrared absorbing glass / resin film / dielectric multilayer film 2 (rear surface). From the obtained data of spectral characteristics, the properties shown in the table below were calculated. FIG. 6 shows the spectral transmittance curve of the optical filter of Example 4-1. Examples 4-1 to 4-8 are working examples, and Example 4-9 is a comparative example.

[0220] [Table 12]

[0221] From the above results, it can be seen that the optical filters of Examples 4-1 to 4-8 have high transmittance in the visible light region and high blocking properties in the near-infrared region over a wide range of 700 to 1200 nm, and that the generation of ripples is suppressed because the change in visible light transmittance is small even at high incident angles, and that the generation of stray light is also suppressed because the reflection characteristics are small at both incident surfaces. The optical filter in Example 4-9 has an average transmittance of T 450-600(0deg)AVE and average transmittance T 450-600(50deg)AVEThe difference between the incident angle and the visible light transmittance is large, that is, the change in visible light transmittance is large at high incident angles. Also, the optical filter of Example 4-9 has high reflectivity at both incident surfaces. Although the dielectric multilayer film 3-5 used in Example 4-9 has excellent light blocking properties in the near-infrared region, it is likely that ripples will occur in the visible light region at high incident angles, and stray light will be easily generated due to its high reflectivity.

[0222] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2021-113059) filed on July 7, 2021, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0223] The optical filter of the present invention suppresses ripple and stray light in the visible light region, and has spectral characteristics that are excellent in transmittance in the visible light region and blocking of near-infrared light, and is useful for applications in imaging devices, such as cameras and sensors for transport aircraft, which have seen increasing performance in recent years. [Explanation of symbols]

[0224] 1B, 1C...optical filter, 10...substrate, 11...near-infrared absorbing glass, 12, 12A, 12B...resin film, 20A, 20B...dielectric multilayer film

Claims

1. An optical filter comprising a substrate, a dielectric multilayer film 1 laminated on one main surface side of the substrate, and a dielectric multilayer film 2 laminated on the other main surface side of the substrate, the substrate has a near-infrared absorbing glass and at least one resin film layer, the resin film has a total thickness of 10 μm or less, and the at least one resin film contains a resin and a dye (NIR1); The optical filter satisfies all of the following spectral characteristics (i-1) to (i-5), (i-7), (i-8), (i-12) and (i-14). (i-1) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T ４５０－６００（０ｄｅｇ）ＡＶＥ More than 85% (i-2) In the spectral transmittance curve at an incident angle of 0 degrees, the maximum transmittance T ４５０－６００（０ｄｅｇ）ＭＡＸ More than 90% (i-3) The average transmittance T ４５０－６００（０ｄｅｇ）ＡＶＥ and the average transmittance T of the wavelength of 450 to 600 nm in the spectral transmittance curve at an incident angle of 50 degrees ４５０－６００（５０ｄｅｇ）ＡＶＥ The absolute difference between (i-4) In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance T at a wavelength of 450 nm ４５０（０ｄｅｇ） More than 80% (i-5) Wavelength IR50 at which the transmittance is 50% in the spectral transmittance curve at an incident angle of 0 degrees （０ｄｅｇ） is in the range of 610 to 650 nm (i-7) In the spectral transmittance curve at an incident angle of 0 degrees, the average transmittance T ７００－１０００（０ｄｅｇ）ＡＶＥ is less than 2% (i-8) In the spectral transmittance curve at an incident angle of 50 degrees, the average transmittance T ７００－１０００（５０ｄｅｇ）ＡＶＥ is less than 2% (i-12) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 at a wavelength of 600 to 1200 nm ６００－１２００（５ｄｅｇ）ＭＡＸ is less than 45% (i-14) When the dielectric multilayer film 2 side is the incident direction, the maximum reflectance R2 at a wavelength of 600 to 1200 nm in the spectral reflectance curve at an incident angle of 5 degrees ６００－１２００（５ｄｅｇ）ＭＡＸ is less than 45%

2. 2. The optical filter according to claim 1, wherein the optical filter further satisfies the following spectral characteristics (i-15) to (i-18): (i-15) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 at a wavelength of 450 to 600 nm ４５０－６００（５０ｄｅｇ）ＭＡＸ is less than 7% (i-16) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 at a wavelength of 600 to 1200 nm ６００－１２００（５０ｄｅｇ）ＭＡＸ is less than 45% (i-17) When the dielectric multilayer film 2 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R2 at a wavelength of 450 to 600 nm ４５０－６００（５０ｄｅｇ）ＭＡＸ is less than 7% (i-18) When the dielectric multilayer film 2 side is the incident direction, the maximum reflectance R2 at a wavelength of 600 to 1200 nm in the spectral reflectance curve at an incident angle of 50 degrees ６００－１２００（５０ｄｅｇ）ＭＡＸ is less than 45%

3. 2. The optical filter according to claim 1, wherein the optical filter further satisfies all of the following spectral characteristics (i-23) to (i-24) and (i-27) to (i-28). (i-23) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 5 degrees, the maximum reflectance R1 at a wavelength of 700 to 1200 nm ７００－１２００（５ｄｅｇ）ＭＡＸ is less than 45% (i-24) When the dielectric multilayer film 1 side is the incident direction, in the spectral reflectance curve at an incident angle of 50 degrees, the maximum reflectance R1 at a wavelength of 700 to 1200 nm ７００－１２００（５０ｄｅｇ）ＭＡＸ is less than 45% (i-27) When the dielectric multilayer film 2 side is the incident direction, the maximum reflectance R2 at a wavelength of 700 to 1200 nm in the spectral reflectance curve at an incident angle of 5 degrees ７００－１２００（５ｄｅｇ）ＭＡＸ is less than 45% (i-28) When the dielectric multilayer film 2 side is the incident direction, the maximum reflectance R2 at a wavelength of 700 to 1200 nm in the spectral reflectance curve at an incident angle of 50 degrees ７００－１２００（５０ｄｅｇ）ＭＡＸ is less than 45%

4. In the spectral characteristic (i-2), the maximum transmittance T ４５０－６００（０ｄｅｇ）ＭＡＸ 2. The optical filter according to claim 1, wherein the reflectance is 93% or more.

5. In the spectral transmittance curve at an incident angle of 50 degrees, the maximum transmittance T ４５０－６００（５０ｄｅｇ）ＭＡＸ 2. The optical filter according to claim 1, wherein the .lambda.

6. 2. The optical filter according to claim 1, wherein the near-infrared absorbing glass satisfies the following spectral characteristics (iii-1) and (iii-2): (iii-1) Average internal transmittance T for wavelengths of 450 to 600 nm ４５０－６００ＡＶＥ More than 90% (iii-2) Internal transmittance T at a wavelength of 450 nm ４５０ Over 92%

7. 2. The optical filter according to claim 1, wherein the near-infrared absorbing glass satisfies the following spectral characteristics (iii-3) and (iii-4): (iii-3) The wavelength IR50 at which the internal transmittance is 50% is in the range of 625 to 650 nm. (iii-4) Average internal transmittance T for wavelengths of 750 to 1000 nm ７５０－１０００ＡＶＥ is 2.5% or less

8. 2. The optical filter according to claim 1, wherein the near-infrared absorbing glass satisfies the following spectral properties (iii-5) and (iii-6): (iii-5) Maximum internal transmittance T at wavelengths of 1000 to 1200 nm １０００－１２００ＭＡＸ is less than 5% (ii-6) Pre-recorded internal transmittance T ４５０ / Preface Maximum Internal Transmittance T １０００－１２００ＭＡＸ ≥10

9. 2. The optical filter according to claim 1, wherein the resin film satisfies all of the following spectral characteristics (iv-1) to (iv-3): (iv-1) Average internal transmittance T for wavelengths of 450 to 600 nm ４５０－６００ＡＶＥ Over 93% (iv-2) Maximum internal transmittance T at wavelengths of 450 to 600 nm ４５０－６００ＭＡＸ More than 95% (iv-3) Internal transmittance T at a wavelength of 450 nm ４５０ Over 86%

10. 2. The optical filter according to claim 1, wherein the resin film satisfies all of the following spectral characteristics (iv-4) to (iv-5). (iv-4) The shortest wavelength at which the internal transmittance is 50% in the spectral transmittance curve of wavelengths from 650 to 900 nm is defined as IR50 （Ｓ） The longest wavelength is IR50 （Ｌ） When IR50 （Ｌ） -IR50 （Ｓ） ≧90nm (iv-5) Minimum internal transmittance T at wavelengths of 700 to 800 nm ７００－８００ＭＩＮ is less than 10%

11. the resin film contains at least one of a squarylium compound and a cyanine compound as the dye (NIR1), 2. The optical filter according to claim 1, further comprising at least one of a squarylium compound and a cyanine compound as a dye (NIR2) whose maximum absorption wavelength in the resin is 30 to 130 nm longer than the maximum absorption wavelength of the dye (NIR1) in the resin.

12. 2. The optical filter according to claim 1, wherein the resin film has one or two layers.

13. An imaging device comprising the optical filter according to any one of claims 1 to 12.

Images